1. Field of the Invention
This invention has particular use in the mining, road planing and earth digging fields. More specifically the invention relates to means for affixing removable members such as cutter bit lugs to a base member such as the driven element of a mining machine or the like. It has particular application to cutter bit lugs and base members whereby the lugs may be easily and quickly installed or removed and replaced, all without damage to the driven element or base member. In like manner the invention may be utilized for removably securing the working element of a road working machine to the driven element thereof or for removably securing the digging tooth to the driven element of an earth digging or dipping machine.
2. Description of the Prior Art
No search of the United States Patent art has been made in connection with this invention. There is some known United States Patent Art, however, which is relevant. In the past, for example, it has been found desirable to provide means for quickly and easily removing and replacing worn bits from the lugs provided to carry them. U.S. Pat. No. 2,965,365 discloses quite satisfactory arrangements for accomplishing this. Means for retaining a rotatable bit within a lug of a mining machine in such manner that the bit may be readily replaced are shown in U.S. Pat. No. 3,397,012. Other such means are disclosed in U.S. Pat. No. 3,114,537. In U.S. Pat. No. 3,622,206 similar means are shown for enabling quick and easy removal of a non-rotatable bit from a bit carrying lug.
In addition to various arrangements for permitting the ready removal of worn bits, some of which are alluded to above, the prior art recognized the importance of also providing arrangements by means of which the bit carrying lug itself could be easily and readily removed from the base member on which it was mounted. U.S. Pat. No. 3,338,634, for example, discloses a pin arrangement by means of which a bit carrying lug or block may be removed from the base member or driven element of a mining machine and the like. This particular arrangement, however, placed a great deal of strain on the pin used to connect the block to the base member. U.S. Pat. No Re. 28,310 described a pin-on-block arrangement for removably securing a block to the driven element of a mining machine or the like in which pins were used to effect the connection, the arrangement being such, however, that most of the stress resulting from the cutting forces arising during the mining or digging functions were taken off the pin. This latter arrangement, while quite satisfactory in many respects, required a certain amount of room for manipulation of the pins in securing the removable blocks to the base members; it was not possible to place such blocks in flush side-by-side relationship on a driven member.
There are other patents which disclose various ways of not only removably affixing bits, teeth and the like to suitable lugs or blocks provided therefor, but also for removably affixing the lugs or blocks to the driven element of a mining or digging machine and the like. Some of these, for example, were applicable to "plumb-bob" bits. These prior known arrangements, while generally satisfactory in many respects, did require a relatively large amount of space to accommodate the various means for affixing the removable lug or block to the driven element of the working machine whatever it was.